Grinding wheel



Bdldlfifl? Fatented July 3, 1962 3,tl4l,77 GRINDING WHEEL Edward K. Mofliy, Pauli, Pas, assignor to A. P. de Sanno & Son, Incorporated, Phoenixville, Pa, a corporation of Iennsylvania Filed Sept. 21, I959, Ser. No. 841,253 1 Claim. (Cl. 51-495) The present invention relates to abrasive grinding wheels and the methods of manufacture thereof.

This application has been divided and the subject matter relating to the method has been embodied in divisional application Serial No. 26,042, filed May 2, 1960, for Method of Making Grinding Wheel, now abandoned.

A purpose of the invention is to simplify the mounting of abrasive grinding wheels by avoiding the need for a flange nut and a wrench.

A further purpose is to permit more ready removal of a grinding wheel when the flange nut becomes bunged or otherwise destroyed.

A further purpose is to eliminate the jam-nut tendency which has been prevalent in grinding wheel mountings.

A further purpose is to make grinding wheels safer against possible unintended release from the spindle.

A further purpose is to make Wheels safer against buckling under grinding pressure or abuse.

Further purposes appear in the specification and in the claim.

In the drawings I have chosen to illustrate a few only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

FIGURE 1 is a fragmentary end elevation from the side remote from the spindle, showing the preferred embodiment of the grinding wheel of the invention.

FIGURE 2 is an exploded axial section of the mounting of the grinding wheel of the invention.

FIGURE 3 is a fragmentary axial section showing the completely assembled mounting of the grinding wheel of the invention.

FIGURE 4 is a fragmentary end elevation similar to FIGURE 1 showing a variation.

FIGURE 5 is a central vertical section showing the first step in molding the grinding wheel of the invention.

FIGURE 6 is a view similar to FIGURE 5 showing the completion of the molding of the grinding wheel of the invention.

FIGURE 7 is an enlarged fragmentary view similar to FIGURE 6 showing the hub portion of the grinding Wheel of the invention in the variant form of FIGURE 4.

Describing in illustration but not in limitation and referring to the drawing:

In conventional practice for mounting grinding wheels of the character provided with raised hubs, or as sometimes mentioned in the art, depressed center discs, the grinding Wheel is engaged on the spindle side with an adapter flange which receives the raised hub and also extends out over a portion of the disc of the wheel, the adapter flange being threaded on the threaded end of the spindle. At the opposed side remote from the spindle, a flange nut is threaded on the end of the spindle and tightened so as to clamp the hub of the wheel between the adapter flange on the spindle side and the flange portion of the flange nut on the other side.

This practice of mounting has given rise to difficulty and annoyance from time to time.

' It will be evident that under most favorable conditions, it is necessary for the operator in removing the grinding wheel to apply a wrench, usually an Allen Wrench, to the wrench opening at the end of the flange nut. When the same wheel or another wheel is to be mounted, it is necessary to thread the flange nut in place. Under most favorable conditions, therefore, the operator must have both the flange nut and the Allen Wrench available when the assembly is to be made.

It should be noted, however, that the fact that the flange nut and the adapter flange are both threaded on the spindle gives rise to a jam-nut effect applied between the adapter flange and the flange nut, so that it may be very difficult in the individual case to remove the flange nut. The amount of force required is such that the flange nut may be subjected to abuse as by hammering on the Wrench, and a condition may result in which removal of the flange nut except by a chisel or the like becomes very diflicult.

Efforts have been made in straight disc grinding wheels, that is, those without raised hubs, to incorporate a nut at the hub of the grinding wheel by cementing the nut to the hub. This has the advantage that a separate flange nut is not required. There is, however, the disadvantage that if the wheel is subjected to lateral forces during service there is danger that the cement may be detached and the wheel may come off the spindle and cause a serious safety hazard.

The present invention is concerned with the production of a grinding wheel which will avoid these difliculties. The grinding wheel of the invention includes a comolded nut which has an interlock with the wheel tending to hold the wheel in place. The nut is rigidly connected to a flange on the side of the wheel remote from the spindle and the flange is also desirably comolded with the wheel. There is thus in the preferred embodiment both axial and radial interlock between the combined flange-and-nut and the wheel.

Furthermore, the presence of the flange on the side of the hub remote from the spindle provides increased safety in case of the possibility that the wheel might detach from the nut.

In the present invention the nut looks the wheel against an adapter flange but the adapter flange is not itself threaded on the spindle so that the jam-nut effect which previously made it diflicult to remove the wheel no longer exists.

Furthermore, in the present invention it is possible to grasp the outside of the wheel and use this turning force of the hands to remove or apply the wheel without the necessity of using a separate wrench. There is, therefore, less likelihood that damage to wrench-engaging surfaces would make it impossible to remove the wheel.

The nut in the present invention is accurately centered with respect to the wheel by comolding and the extension of the nut into the adapter flange assures proper centering of the adapter flange, so that proper balance of the grinding wheel assembly is assured.

The presence of the raised hub in comolded relation to the nut and flange assures a much stronger, safer wheel than has heretofore been produced, with less danger of breakage or injury to personnel.

Considering now the drawings in detail, the grinding wheel of the invention comprises a flat disc 20 which consists of layers of abrasive 21 which are alternating with layers of reenforcing 22, the entire structure being held together by a resin bond.

The abrasive may be any one of the well known abrasive materials, suitably particles of silicon carbide, aluminum oxide, emory, diamond, or any other suitable abrasive.

The reenforcing may be a fabric of any suitable material, such as nylon, rayon, cotton, glass or any other suitable reenforcing fabric, as well known in the art.

The bond will suitably be an organic resin such as phenol formaldehyde, urea formaldehyde, melamineformaldehyde, epoxy resin, or any other well known resin bond, or a rubber bond, or a bond composed of a mixture of resin and rubber.

The alternate layers of abrasive and reenforcing of the disc portion extends continuously to form a raised hub 23 at the spindle side of the wheel near the axis.

Extending axially through the wheel is a spindle nut 24, suitably of steel, which has a threaded central opening 25 which is adapted to thread on the threaded end 26 of spindle 27 beyond the spindle shoulder 28.

At its outer circumference the spindle nut has a groove 30, suitably an annular recess, into which the reenforcing and abrasive of the hub 23 extend, and to which the hub is united by comolding.

Rigidly connected as by welding to the nut 24- is a flange 3d at the end of the nut remote from the spindle, suitably also of steel.

The flange is suitably held in a shoulder portion 32 on the nut.

The flange has axial interlock projections 33 at spaced intervals around its circumference suitably formed by stamping and taking the shape of buttons which are in comolded relation with the hub 23.

In the preferred embodiment of FIGURES l and 2, the flange also has radial interlock projections 34 similar to gear teeth which are in comolded relation with the hub 23. In the form of FIGURES 4 and 7, however, the radial interlock projections 34 have been omitted.

Corresponding to the axial interlock projections 33 there are depressions 35 on the flange on the side of the wheel remote from the spindle and the depressions are suited to receive a spanner wrench which can be used in tightening or removing the wheel in case the grip of the hand on the rim of the wheel does not provide sufficient force.

On the side of the wheel adjoining the spindle, the spindle nut 24- protrudes at 36 and receives and guides a bore 37 on adapter flange 38 so as to center the adapter flange.

The adapter flange has a counterbore 39 which closely surrounds the threaded portion of the spindle 26 beyond the spindle nut. At the side of the adapter flange remote from the grinding wheel it has a flat surface 40 which is adapted to engage the shoulder portion 28 of the spindle or in more usual practice to engage the outer of spacer washers 4-1.

On the side of the spindle adjoining the grinding wheel, the adapter flange has a recess 42, which surrounds and clears from the raised hub of the wheel and radially outwardly of the recess the adapter flange has a straight flange portion 43 which engages and supports the inner part of the disc portion of the wheel on the spindle side.

Thus in assembling the wheel on the spindle in accordance with the present invention the washers all slip on first and the adapter flange merely slips on and is not threaded on. Then the wheel, and the spindle nut and flange as a unit are threaded on and tightened by the hands applied to the rim of the wheel like a wrench. This is all that is required.

In removing the wheel it is merely necessary to reverse the process. If the wheel is too tight to remove by the hands, a spanner wrench may be used, but this is normally not necessary.

In molding the wheel of the invention, the mold consists of a mold bottom 44 which has a central axial opening 45, a flat top 46 which is of disc shape and surround ed by a barrel 47 which is desirably separable.

Departing from previous practice, the mold bottom is provided with a flange bottom support 48 which suitably has the thickness of the mold bottom and which occupies the circular opening 45. The mold flange bottom is desirably provided with a pin-receiving opening 50 at the center.

As initially set up, the mold is placed on a flat surface such as a table with the mold barrel and bottom supported on plates "51. Therefore the flange bottom support 48 which rests on the table 52 forms a depression 53 at the center of the mold, and into this depression is placed the flange 31 and the spindle nut 24 which are united together as by welding, the upper surface of the flange at 54- being flush width the bottom of the mold and the flange and nut central with respect to the mold. Then a pin 55 is rested on the spindle nut, the pin having an upper portion 56 which is circular and of the same diameter as the outside of the nut and extends upwardly in prolongation of it. The pin 55 has an extension 57 of reduced diameter which extends down into the central opening 5% of the flange bottom support 48 and suitably engages the insides of the threads of the nut.

With the mold parts in the position of FIGURE 5, the grinding wheel is built up according to previous practice, inserting the alternate layers of abrasive and reenforcing 21 and 22 with the suitable binder, as well known, to a thickness which may be considerably in excess of that shown in FIGURE 5, until the built-up wheel surrounds the nut and also the pin portion 56. It will be evident that there are openings in the center of the reenforcing to pass the nut 24 and the pin portion 56.

Next the spacer blocks 51 are removed, after which the flange and spindle nut move upwardly relatively to the mold until the top of the flange bottom support 48 is flush with the bottom of the mold and the bottom of the flange is flush with the bottom of the mold, as shown in FIGURE 6. This forms the raised hub portion 23. A mold cover or top 58 suitably of steel is then applied to the mold, which fits within the interior circumference 6t} of the barrel and which closely fits the outside of the pin portion 56 and the nut. The cover has a recess 60 which receives and forms the raised hub portion.

Now the pressure is applied axially between the mold cover 58 and the mold bottom 44 in any suitable press, as well known, so as to form the wheel, comolding the hub against the interlock on the nut and the interlocks, which may be both axial and radial or entirely axial or entirely radial, on the flange.

The wheel will then be suitably processed to cure the bond as desired.

In the finished wheel, it will be evident that the side of the flange remote from the spindle is desirably flush with the disc at that side of the Wheel.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits'of my invention without copying the structure shown, and 1 therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claim.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

A grinding wheel mounting including a spindle having a threaded end, in combination with a grinding wheel having a body provided with a radially outer flat disclike portion and a raised hub portion near the center of the wheel at the side of the grinding wheel toward the spindle and interconnected with the disc-like portion, and having a spindle nut threaded on the spindle, having a hub-like portion and having a flange rigidly connected with the hub-like portion and extending radially outwardly beyond the hub-like portion of the spindle nuton the side of the grinding wheel remote from the spindle, the flange portion of the spindle nut and the disc-like portion of the body being flush at the side of the grinding wheel remote from the spindle, the hub-like portion of the spindle nut having a groove which is in co-molded interlocked relation with the material of the raised hub, and the flange portion of the spindle nut having axial projections which are in co-molded interlocked relation with the material of the raised hub, the outer radial con- 5 6 fines of the flange portion being Within the raised hub References Cited in the file of this patent portion of the body, the hub-like portion of the spindle nut extending axially toward the spindle beyond the raised UNITED STATES PATENTS hub portion and in further combination with an adapter 2,186,402 Bowen Jan. 9, 1940 flange surrounding the spindle but free from interthread- 5 2,250,580 Gregory July 29, 1941 ing therewith, having a center opening which surrounds 2,278,301 Bauer Mar. 31, 1942 and engages the extension from the hub-like portion of 2,590,697 Grove Mar. 25, 1952 the spindle nut, having a rim which engages the disc- 2,806,331 Hoye Sept. 17, 1957 like portion of the Wheel body, and having a recess which 2,843,469 Miller et al. July 15, 1958 receives the raised hub of the wheel body. 10 2,950,582 Beauchaine Aug. 30, 1960 

